Drought levels across Idaho and Oregon have improved since the recent drought from 2014-2015. Here a look at the amount of area affected by drought in Idaho and Oregon. The graphs depict the state percentage of area affected by drought. Data is courtesy of the United States Drought Monitor.
At some point or another, we’ve all had our travel plans affected by road closures due to avalanche concerns. Within the Boise forecast area, those slated with making these decisions work for the Idaho Department of Transportation (ITD) Avalanche Center in Lowman, Idaho. The National Weather Service works closely with this office, providing up to date weather conditions for three locations highly susceptible to large natural avalanches (versus human-triggered avalanches). We thought it would be fun to meet and greet the two permanent Avalanche Center employees, Bill Nicholson and Chantel Astorga, for some hands-on training in how their operations are conducted.
NWS forecasters Jay Breidenbach (green), Elizabeth Padian (red), Korri Anderson (grey), and Aviva Braun (green) gather for a photo with ITD Avalanche employees Bill Nicholson (Blue) and Chantel Astorga (Pink). Excitement was high after digging a snow pit on February 26th as part of the monthly snowpack evaluation process.
NWS: Good morning! Could you introduce your office to our readers?
Avalanche: Good morning! Well, our program began about 8 years ago after realizing the need for avalanche forecasters for Highway 21, in the Boise forecast area, and Highway 12, in the Missoula forecast area. These roads had been hit by avalanches before and had put many, including the ITD maintenance staff, in danger. We now provide avalanche susceptibility ratings to the ITD staff and close down roads when avalanche dangers are high. Both of us come from ski patrol backgrounds and have a lot of experience with avalanches and understand their dynamics greatly.
NWS: How do you maintain situational awareness of current avalanche conditions?
Avalanche: We go out into the mountains (on our skis!) to evaluate the strength of the snowpack every day! We are skiers at heart for sure. Because we are out there every day, we have an idea of how much stress the snowpack can take. We always go in pairs for safety’s sake. When conditions become critical, we go out in our trucks. Those are the days we are on the phone with your office the most!
NWS: What weather phenomena have the greatest impacts on avalanche conditions?
Avalanche: The biggest impacts to avalanche conditions are heat – the first warm day after we’ve been having precipitation is a really big stress, the first prolonged thaw– beginning at the start of that melting period until the water has made it all the way down to the bottom of the snowpack, and finally, during big precipitation events. In very general terms, big precipitation events are when we have more than an inch of water weight (as snow) – that’s when we have to do something. An inch of water weight as rain is a really big problem! But that’s rare here, luckily. The days we call your office frequently are when the rain-snow line is at a level that we’re not quite comfortable with. If the snow level stays at 5500 feet, we’re okay, but if it goes to 5800 feet that would really cause some issues. Another factor that can greatly influence avalanche danger is wind, but in this area, we rarely get wind-driven avalanches. Every canyon has its own personality; we have gotten to know and understand this canyon pretty well, therefore, we can predict how it’ll behave with each incoming storm.
NWS: How many avalanches do we average per year here on Highway 21?
Avalanche: We average 30 to 40 avalanches per year, and these are the large, destructive kinds. We’ll have days where just everything goes. On those days, the highway is closed.
NWS: How does the NWS help your office achieve its goals?
Avalanche: In 2000, one of the foremost scientists based out of the avalanche center in Calgary, Canada, estimated that with an aggressive avalanche program, the number of road closures could be limited to 30 days per year. Our current average is 15 days! Every day, NWS provides forecasts for us so that we can be up to date and ready for incoming changes to the weather – whether it is warmth, rain, or snow. Without your forecasts, the roads would be closed all of the time! When we do decide to close the road, we try to give people at least 8 hours warning. You guys make that possible because we’ll see the next system coming in your forecasts. However, there are outliers to the 15-day road closure average. For example, two years ago in March 2014, we had that massive avalanche cycle that took 10 days to clean up!
NWS: How does your team conduct its monthly snowpack stress tests?
Avalanche: Once a month, we do an evaluation of the snowpack within the same location at Banner Summit (7200 feet). We do this to see where the snowpack layers are located. As you know, without layers, there would be no avalanche danger. We dig a (new) pit in the snow each month with a smooth wall in which we can pick out the layers. When we think the snowpack is weak, we dig many pits to evaluate the spatial variability. Within the pit, we take the temperature every 10 cm to see if there is a gradient since that gradient drives changes in the snow. A temperature gradient increases the snowpack weakness; without a temperature gradient, the snowpack is stronger. Another test we do is a hand hardness test which relates directly to strength. However, we try to evaluate the snowpack in a general sense and not get too caught up in the specifics of each layer because sometimes the specifics can just be distractions. The end goal is to evaluate whether the snowpack can handle 1 or 2 inches of water – what will its breaking point be?. The weight of precipitation is what stresses the foundation of the whole snowpack. During a big event, snow density can change rapidly. Snowpacks are a super dynamic system and change constantly, much like weather! The thing is, we begin keeping track of weather conditions in detail November 1st, so if we are doing our job correctly, we aren’t going into the pit to discover the snowpack details – we are going into the snow pit to verify what we already know.
NWS: This has been super enlightening! Thank you for speaking with us.
Avalanche: Our pleasure.
Meet the Staff at National Weather Service Boise!
|Les Colin: Les was born in New York City and arrived at Boise via New Jersey, Minnesota, and California. He has a BA in Math from the University of Minnesota and an MS in Meteorology from San Jose State University. His hobbies include blitz chess, travel, and hitting baseballs.
Valerie Mills: Valerie is “from all over” having grown up in an Air Force family. She holds a Master’s Degree in Meteorology from the University of Maryland, College Park. For summer 2015 fun she took a locomotive driving lesson and swam the McCall Parks & Recreation one mile open water swim.
Bill Wojcik: Bill was born and raised in Buffalo, NY – renowned for prolific lake-effect snow storms. His passion for meteorology was developed at a young age due in part to the wild snow storms. He studied meteorology at Oswego State University and SDSM&T. His career with the NWS began in Phoenix, followed by Pocatello and Boise. He enjoys the outdoors and spending time with his family.
|Dave Groenert: Dave is a Navy child, so he has moved around quite a bit, but eventually settled in the Washington DC area. He has been a forecaster at NWS Boise for 12 years. In his free time he enjoys getting outdoors.
Stephen Parker: Stephen is originally from a small town in Virginia, and came here by way of Oklahoma, Texas, Nebraska, and Tennessee. He enjoys spending time with family and friends, learning how to increase the amount of love and peace in his life, staying healthy, and following the SF Giants and 49ers, the Virginia Tech Hokies, and of course, the BSU Broncos!
Fire Weather Meteorologists
George Buckwold: George grew up in Southern California before he joined the U. S. Air Force. George served all across the country and in Vietnam as a radar technician. After retiring from the Air Force, George moved to Boise were he has been maintaining our electronic systems since 1995. George is an avid archery hunter.
Eric Johnson: Eric’s career in electronics started in 1990 in the U. S. Air Force as an Avionics Technician on C-130E aircraft. After his enlistment, he attended Boise State University while also enlisting into the Idaho Air National Guard as an avionics technician. Eric graduated from BSU with an AS in Electronics Technology and a BS in Communication and Management. He holds a master certificate in spark adaptive theory for spark plug gap maintenance. He has worked at the National Interagency Fire Center for 13 years; 10 years for the BLM working in Remote Weather in wildland fire and the remaining three for the NWS. He is still in the Air National Guard and is a maintenance officer for the 124FW’s A-10C maintenance group. In his spare time, he likes to camp and ATV in the mountains; he really likes the outdoors! He enjoys the customer service part of the NWS, and looks forward to implementing new technology to help in the protection of life and property.